Regulation and expression of the metal citrate transporter CitM of Bacillus subtilis

The main topic of this thesis is the regulation of transcription of the citM gene of Bacillus subtilis, encoding the major metal citrate transporter. CitM belongs to a small family of secondary transport proteins, the MeCit family, that is comprised of 12 members. CitM mediates the transport of metal citrate (Me2+*:citrate3-) across the cell membrane in an electrogenic pmf-driven manner, meaning that at least two protons are cotransported. The divalent metal ions that can be taken up in complex with nitrate include magnesium, manganese, nickel, cobalt and zinc.